The invention relates to a locking device which can be locked without a key but necessitates a key for unlocking.
Such a device is very useful for applications in which it is desired to be able to use a lock without it being automatically locked at every utilization. This is the case for example with a petrol filler closure flap for an automobile vehicle, a luggage lock, or an apartment door lock.
In general, with such devices the locking and unlocking are effected by means of a key, independently of the lock, even when the bolt is combined with the lock.